Selecting text in Gmail is then deselected by Firefox and only in Firefox.
Double-clicking a word or click and drag to select is removed by Firefox in Gmail on the first attempt. Subsequent attempts are successful.
Action: Open email in Gmail tab in Firefox. Double-click or click and drag a selection.
Result: Selection is highlighted for a couple seconds and then is unhighlighted (deselected). Cannot copy the original selection.
Expected result: Selection remains highlighted and can be copied by keyboard command or right-click context menu "Copy".
Attempted correction: A second attempt to highlight is successful as normal. Selection remains highlighted and available for copy function.
This is ONLY in Firefox. Chrome acts as expected first time, every time.